Each buffer strip shall be planted with at least two trees and/or shrubs every 10 linear feet. The remainder of each buffer strip shall be landscaped in grass, ground cover, or other vegetation. If woodlands are relocated within the required landscaped area, preservation may substitute for the required trees and/or shrubs. If woodlands are located in only part of the required landscaped area, the number of trees and/or shrubs required may be proportionally reduced.